共查询到20条相似文献,搜索用时 109 毫秒
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为提高天然沸石除氟性能,比较了不同方法改性的沸石对水样的除氟效果,并通过静态吸附实验对其中效果最好的EDTA-NaOH—Fe2(SO4)3改性沸石进行了除氟条件优化。结果表明;以EDTA-NaOH—Fe2(SO4)3改性沸石除氟时,EDTA、NaOH和Fe2(SO4)3的最佳浓度分别为0.2mol·L-1、1.0mol·L-1和1.0mol·L-1,最佳粒径、投料量、水样pH值、吸附时间和水样温度分别为60目、5.0g·(100mL)-1、7.0、60min和50℃。含氟20.0mg·L-1的高氟水经改性沸石处理2次后,F-浓度降至1.0mg·L-1以下,符合国家生活饮用水标准。 相似文献
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研究应用酸碱处理,硫酸铁浸泡等方法来改性天然沸石,探讨其除氟性能,并得到了最佳的改性途径:40~80目斜发沸石用去离子水冲洗、烘干,然后在1.38 mol/L硫酸溶液中搅拌、浸泡24 h,洗净烘干,最后在Fe~(3+)浓度为1.5 mol/L的硫酸铁溶液中煮沸、搅拌2 h.采用静态和动态相结合的方法确定了影响沸石除氟的多种因素,并对除氟过程的吸附模式、热力学性质进行了研究. 相似文献
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沸石用于饮用水氟含量控制的研究 总被引:2,自引:0,他引:2
饮水中氟化物的含量对人体的健康有重大影响。通过对新型氟试纸和沸石除氟的性能分析,提出在对饮用水中氟含量进行氟试纸动态监测的基础上,配合以离子选择电极法进行准确检测,采用沸石进行除氟,从而控制饮用水中氟含量的方法是有优越性的。 相似文献
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新型降氟材料──活化沸石 总被引:17,自引:0,他引:17
本文进行了活化沸石降氟试验,结果表明活化沸石具有较好的降氟性能,同时对水体中共存的重金属离子,色度,硬度,碱度等均有降除作用,现场应用效果良好。 相似文献
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活化沸石的饮用水除氟工艺研究 总被引:16,自引:0,他引:16
通过静态实验研究表明活化沸石降氟吸附反应较快,其最佳pH值范围为5.5~6.5;再生液pH值在小于4或大于11时再生效果良好。采用动态实验考察,结果表明活化沸石比天然沸石的除氟容量提高了65%,处理水量分别为44L/kg,28L/kg,采用2%的硫酸铝浸泡再生,再生率约为80%,且多次再生后沸石柱除氟效率保持稳定。采用粘土为助沉淀剂与钙盐联合对使用后的再生液进行更新回用,达到了满意的效果。 相似文献
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人造沸石处理钽铌厂矿石分解工序含氟废水的研究 总被引:3,自引:0,他引:3
对含氟量为1836mg/L的钽铌厂矿石分解工序碱性废水用沸石进行除氟试验。对未改性沸石.试验了沸石用量、废水初始浓度和振荡吸附时间对氟去除率的影响,发现未改性沸石氟去除率不高。用AlCl3溶液对其改性后,去除率明显升高,可达95%以上,处理后废水残氟量可降到10mg/L以下,达到国家污水综合排放标准中的一级标准。 相似文献
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以阜新天然丝光沸石为原料,依次使用0.2 mol/L的EDTA溶液25℃恒温浸泡2h、1.0 mol/L的NaOH溶液煮沸1h、0.15 mol/L的KAl(SO4)2溶液25℃恒温浸泡10 h处理后得到改性沸石.利用X射线粉末衍射(XRD)、扫描电镜(SEM)对改性前后的样品进行分析,通过静态除氟实验和动态除氟实验结合,考查改性沸石除氟实验过程的影响因素和除氟效果,并对天然沸石的改性、除氟和再生过程的机理进行了探讨.结果表明:用改性沸石做吸附剂,可使氟离子浓度为80 mg/L的废水浓度降低到10 mg/L以下,达到国家工业废水排放标准,且沸石再生使用效果良好. 相似文献
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用呼和浩特郊区榆林地区的丝光沸石对内蒙古土左旗黑河村典型的高氟、高砷饮水进行了净化实验研究。结果表明,当地沸石经改造处理,对饮水除砷、降氟有较理想的作用。实验中研究了沸石的改型方法和在饮水净化中应用的工艺条件,为低品位沸石的应用找到了新的途径。 相似文献
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改性凹凸棒石和沸石对氨氮废水吸附性能的研究 总被引:1,自引:0,他引:1
采用焙烧、钠化、酸化和碱化4种改性方法对天然凹凸棒石和沸石进行改性,其中碱化改性对氨氮吸附能力提高最大,研究了碱化样品的结构及对氨氮废水的吸附性能。结果表明,碱改性品在氨氮溶液初始浓度300 mg/L,pH值2.5~8.0时,对氨氮的吸附量较高;对氨氮的吸附等温线符合Freund lich和Langmu ir方程式。同时,对氨氮的吸附动力学符合准二级吸附动力学模型,并以化学吸附为主。用于畜禽废水处理中,对氨氮去除率最高达到87.6%。 相似文献
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Defluoridation of drinking water using a ceramic filter decorated with iron oxide-biochar composites
Cynthia Mandoreba Willis Gwenzi Nhamo Chaukura 《International Journal of Applied Ceramic Technology》2021,18(4):1321-1329
While effective defluoridation methods have been developed, most of them are expensive and difficult to apply at a household level. One safe, low-cost, decentralized water treatment method which is attracting research attention is the use of ceramic filters (CFs). Few studies have explored the use of biochar composites in CFs for defluoridation of water, with the bulk of them being based on batch and column experiments. The aim of this work was to develop, and evaluate a laboratory-scale, low-cost CF using clay, sawdust, and iron oxide-biochar (FBC) for fluoride removal in synthetic and real water samples. Three CFs were fabricated with varying FBC content (0%, 5%, and 10%). Water absorption, apparent porosity, and flow rate decreased with decreasing FBC content, while the impact strength increased with decreasing FBC content. The CFs reduced the fluoride concentration of both the ground water, and synthetic water to below the WHO recommended limit (1.5 mg/L). While further studies are required to optimize the CF, the results demonstrate that a CF decorated with FBC composites is effective for defluoridation of drinking water. 相似文献
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《分离科学与技术》2012,47(14):3676-3694
Abstract In this study the applicability of Zirconium ion impregnated coconut fiber carbon (ZICFC) as an adsorbent for fluoride removal from water was investigated. The dependence of fluoride adsorption on the physicochemical properties includes pH, agitation time, adsorbent dosage, temperature, and the initial concentration of the adsorbate. Maximum defluoridation was obtained at an original pH value of 4.0 with a rapid 93% adsorption being achieved within 10 min of contact with ZICFC. Adsorption data for fluoride onto ZICFC were better correlated to the Langmuir isotherm and pseudo-second order chemical reaction provided the best fit for the experimental data as obtained from kinetic studies. A combination of chemisorption and physisorption processes in hand with intraparticle diffusion, account for the high defluoridation ability of ZICFC, with the thermodynamic parameters indicating an endothermic phenomenon. The fluoride adsorption capacity of ZICFC when compared with those of other commonly used fluoride adsorbents highlights the substantial improvement in fluoride adsorption capacity of coconut fiber carbon on zirconium impregnation. 相似文献
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引 言纤维素含量约占 50 %的生物质资源 ,是非常有应用前景的可再生资源 .目前用于大规模处理生物质资源的方法有酸水解、热分解和水蒸气蒸爆等 .酸水解的目标是最大限度地获得单糖 ,它又可发为浓酸水角[1] 与稀酸水解[2 ] .酸水解具有以下缺点 :①反应速度较慢 (最大 0 .1min- 1) ;②反应器腐蚀严重 ;③需国收酸 (浓酸水解 )以及废水处理等 .热分解的目标是生成燃料 ,Antal等[3] 对此进行大量的研究 ,此法设备与工艺均较简单 ,但存在着产品价值较低、污染严重等问题 .水蒸气蒸爆因水解率低 ,一般只作为预处理技术[4 ] .另外还有人… 相似文献
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利用粉煤灰合成沸石的方法很多,其中水热法合成沸石因操作简单、能耗低被认为是将粉煤灰基沸石商业化最可行的手段。采用水热法将国内外不同产地的几种粉煤灰合成沸石,并通过X射线衍射(XRD)、X射线荧光光谱(XRF)、热重分析(TG-DTA)、扫描电镜(SEM)等手段对合成的沸石产品进行表征,并在同一水热合成参数下考察不同粉煤灰合成沸石在品质上的差异。XRD谱图表明,原料中有80%~90%的成分转化为沸石,且沸石主要结晶类型为Na-P1型,也有少量的A型;XRF分析表明,3种粉煤灰基沸石硅铝物质的量比分别为1.61、1.35、1.45,符合XRD谱图的分析结论;TG-DTA表明,合成沸石在500 ℃以上几乎没有质量损失,具有良好的热稳定性;由SEM照片可见,合成的沸石为非球形,表面的纹理可增加沸石比表面积,结晶状态好。整个实验过程简单、成本低、合成沸石样品品质较高,由此可见通过水热法将粉煤灰合成沸石产品具有巨大的商业化潜力。 相似文献
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Hydrocracking of diphenylmethane and tetralin over bifunctional NiW sulfide catalysts supported on three kinds of zeolites 总被引:1,自引:0,他引:1
Koichi Sato Yoshiki Iwata Toshikazu Yoneda Akio Nishijima Yasuo Miki Hiromichi Shimada 《Catalysis Today》1998,45(1-4):367-374
Hydrocracking reactions of diphenylmethane and tetralin were carried out over three kinds of zeolites with or without NiW sulfide to discuss the roles of catalytic bifunctionality in two types of hydrocracking reactions. It was found that strong acid sites were not needed for the hydrocracking of diphenylmethane, while the conversion of tetralin required relatively strong acid sites. Ultra-stable Y zeolite with strong acidity exhibited high hydrocracking activity for both reactions. In contrast, mordenite catalysts did not show high activity for either hydrocracking, though isomerization of tetralin and excess hydrocracking to gaseous products proceeded. The superior performances of ultra-stable Y zeolite in the tetralin hydrocracking were suggested to be related to the hydrogen transfer ability. In most cases, the loading of NiW sulfide enhanced catalytic activity. In the diphenylmethane hydrocracking, the role of NiW sulfide was found to supply active hydrogen to the hydrocracking active sites on zeolite and to prevent polymerization of benzyl cations. In the tetralin hydrocracking, the dehydrogenated products from tetralin were re-hydrogenated over NiW sulfide. 相似文献